1. Field of the Invention
The present invention relates generally to agricultural equipment and more specifically to bale wagons.
2. Description of the Prior Art
With the trend in farming practices towards increased mechanisation, the automatic bale wagon, such as the type illustrated in U.S. Pat. No. 3,610,442 and Canadian Pat. No. 902,003 has been gaining in acceptance as an essential farm implement. In these bale wagons, bales are loaded onto a first receiving table which sequentially moves two or more bales in end-to-end relaionship onto a second transfer table, whereupon a tier of bales is accumulated. When a full complement of bales for a tier has been loaded upon the second transfer table, the latter is elevated from a somewhat horizontal position to a substantial vertical position to dispose the tier of bales either against a rolling rack upon a load bed of the wagon or against the forward face of a previously deposited tier of bales. All operations of the various receiving and transfer tables, rolling rack and final unloading of the load bed are accomplished by hydraulic means and associated fluid circuits and control valves which are operated by appropriate cams, trip members and other means such as described in detail in the aforementioned patent specification.
After accumulating successive bale tiers to form a completed bale stack on the load bed, the bale stack may be transported to a desired location for discharge from the wagon in a composite stack. Bale wagons have now evolved to the point where not only can they pick up individual bales in the field and stack them or retrieve an entire stack, but they are also able automatically to unload the wagon one bale at a time.
Bale wagons of the types hereinbefore described are generally satisfactory when operating in generally flat fields. However, when using these bale wagons in hilly conditions, certain problems are encountered.
When the bale wagon is operated on a downward incline, it has been found that the bale tiers on the load bed tend to fall forwards or take up a curved profile. One solution to this problem has been to leave the transfer table in the upper position after completing the loading of bales on the wagon and whilst the wagon is driven to the desired discharge location. This solution, however, solves only part of the problem since it is necessary to keep the transfer table in its generally horizontal position during the loading operation to accumulate bale layers. Therefore, any previously-loaded bale tiers which tend to fall forwards create an irregular or lossely piled stack which is unacceptable. The tendency for bales to fall backwards when the wagon is operating downhill equally occurs between the second and first table. Similar problems occur during abrupt braking of the wagon.
It is the primary object of the present invention to overcome or attenuate the problem of bales on the load bed becoming disarranged.
According to the present invention a bale wagon comprises a bale transfer table movable between a bale-receiving position and a bale-unloading position in which latter position bales are transferred to a load bed to form a stack of bales comprising a plurality of tiers of bales, retractable bale-retaining means operable to retain the forwardmost tier of bales in position on the load bed and control means operable to automatically retract the bale retaining means when a further tier of bales is transferred to the load bed from the transfer table.
The bale-retainer means may be in the form of a plurality of pivotable tines or fingers engageable with top bales of the front tier under a positive contact pressure. The tines may be spring loaded and movable to an inoperative position against the spring force by means, such as a cam for example, associated with the transfer table. The tines are moved to the inoperative position when a further tier of bales is to be transferred to the load bed from the transfer table or when a stack of bales on the load bed is to be unloaded, either en bloc or bale-by-bale, from the wagon. In an alternative arrangement, the contact pressure of the tines and the retraction of the tines is controlled by a hydraulic actuator.
In still another arrangement and according to another aspect of the invention, the bale-retaining means are pivotally mounted in front of the front tier of bales on the load bed so as to be engageable with the front face of said tier in an operative position and being retractable to an inoperative position clear of said front face to permit the transfer of a further tier of bales to the load bed from the transfer table or to permit unloading of the load bed.
The bale-retaining means may comprise bale-retaining members in the form of two generally vertical side arms interconnected by a transverse arm, the side arms being pivotally mounted and attached to one end of a link the other end of which is operatively connected to the transfer table such that when the transfer table is moved towards the load bed, the side and transverse arms are pivoted clear of the front face of the front tier of bales to the inoperative position.
Still other bale-retaining members may comprise two generally transversely-extending arms pivotally mounted at respective sides of the wagon for pivotal movement between operative and inoperative positions in a transverse plane.
Each transverse arm may be spring loaded to the operative position and have a cranked end operatively associated with the transfer table such that when the latter moves towards the load bed, the transverse arm is moved to the inoperative position. The cranked end of each transverse arm may be connected by a cable to a first lever connected to a rock shaft which also has connected thereto a second lever in engagement with a cam attached to the transfer table, the arrangement being such that when the transfer table is moved towards the load bed the cam is rotated whereby the second lever is moved and rotates the rock shaft and first lever, the latter pulling on the cable to pivot the transverse arm from the operative position to the inoperative position.